University of Helsinki, Dept. of Environmental Sciences, Lahti, Finland.
University of Helsinki, Dept. of Environmental Sciences, Lahti, Finland.
J Hazard Mater. 2014 Jun 15;274:72-8. doi: 10.1016/j.jhazmat.2014.03.065. Epub 2014 Apr 13.
The effect of temperature on the reductive dechlorination in sediments of the PCDD/F-contaminated Kymijoki River, Finland was assessed with 1,2,3,4-tetrachlorodibenzofuran (1,2,3,4-TeCDF) at various temperatures and with co-amendment of 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) in laboratory microcosms. The dechlorination rate of 1,2,3,4-TeCDF increased with incubation temperature, with TeCDF half-lives of 2.1 y at 21°C, 3.9 y at 15°C, and 19.0 y at 4°C. Co-amendment with 2,3,4,6-TeCP reduced the TeCDF half-life to 1.8 y at 21°C. 1,2,3,4-TeCDF was dechlorinated mainly in the lateral position to 1,3,4-TrCDF and then to 1,3-DiCDF over 29 months, but incubation temperature affected the relative molar ratios of the dechlorination products. The abundance of the Dehalococcoides-like Chloroflexi community did not substantially change in microcosms over 24 months incubation at the different temperatures. The dechlorination activity of 1,2,3,4-TeCDF was significantly limited at lower temperatures, which should be considered in predicting the environmental fate of aged PCDD/Fs in sediments of the Kymijoki River.
温度对芬兰基米约基河 PCDD/F 污染沉积物中还原脱氯的影响，通过在不同温度下用 1,2,3,4-四氯二苯并呋喃（1,2,3,4-TeCDF）和 2,3,4,6-四氯苯酚（2,3,4,6-TeCP）共添加来评估。1,2,3,4-TeCDF 的脱氯速率随培养温度的升高而增加，在 21°C 时 1,2,3,4-TeCDF 的半衰期为 2.1 年，在 15°C 时为 3.9 年，在 4°C 时为 19.0 年。2,3,4,6-TeCP 的共添加将 1,2,3,4-TeCDF 的半衰期缩短至 21°C 时的 1.8 年。1,2,3,4-TeCDF 主要在侧位脱氯生成 1,3,4-TrCDF，然后在 29 个月内进一步脱氯生成 1,3-DiCDF，但培养温度会影响脱氯产物的相对摩尔比。在不同温度下培养 24 个月后，氯代拟杆菌样绿弯菌门的丰度在微宇宙中没有明显变化。1,2,3,4-TeCDF 的脱氯活性在较低温度下受到显著限制，在预测基米约基河沉积物中老化 PCDD/Fs 的环境归宿时应予以考虑。
